Wireless system to detect presence of child in a baby car seat

ABSTRACT

A wireless system that detects the presence of a child in a safety seat located in the passenger cabin of a vehicle includes a controller responsive to signals generated by sensors monitoring predefined functions of the vehicle, RFID tag device attached to the safety seat and RFID tag reader mounted in the cabin. The system generates control signals which activate an alarm, open the doors of the vehicle and roll down windows if the child is left in the safety seat of an unattended vehicle.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.11/835,042, filed Aug. 7, 2007, which is a continuation of U.S. patentapplication Ser. No. 11/194,179, filed Aug. 1, 2005, now U.S. Pat. No.7,321,306 B2, which claims priority to Provisional Application Ser. No.60/635,371, filed Dec. 10, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to systems for detecting the presence of occupantsof an automobile. In particular, the invention relates to systems thatdetect the presence of a child in a child's seat without otherpassengers and the automobile is not in an operational mode. In thiscase, corrective action is taken to minimize injuries to the child.

2. Prior Art

Most, if not all, jurisdictions within the United States of Americarequire infants and children of certain age to be strapped into achild's seat when the automobile is in motion. Failure to do so is aninfraction of the law and could result in the operator paying a fine forthe infraction. Even though this law protects infants and children undercertain conditions, it could also cause injuries or even death to theinfant and children it is suppose to protect. One of the conditionsoccurs when an operator parks the vehicle and forgets to remove theoccupant from the child seat. There have been reports in the press thatthe operator leaves an occupant in the baby seat, the temperature soarsor drops and as a result the child or infant suffers injuries. In fact,there have been reports of children and/or infants dying from hightemperatures.

To prevent this unintended result, the prior art has provided systemsthat detect the presence of occupants in an infant seats of unattendedvehicles and sound an alarm on such detection. U.S. Pat. Nos. 5,949,340and 6,714,132 are examples of such prior art systems. Even though thesystems provided in these patents work well for intended purposes, thechild's seat in these systems requires some type of power which isderived from the vehicle, in which the child's seat is mounted. Toobtain power from the vehicle the child's seat is usually wired to theelectrical system of the vehicle. This requirement imposes unnecessaryrestrictions which limits portability of child's seat. In other words,if the child's seat is wired to the vehicle electrical system as isrequired by U.S. Pat. No. 5,949,340, the seat can only be used with thevehicle to which it is wired.

SUMMARY OF THE INVENTION

The system of the present invention is implemented with Radio FrequencyIdentification, hereafter RFID, technology. The RFID technology ispackaged into a RFID tag and a RFID tag reader. The electrical structureof the RFID tag includes an antenna coupled by a switch to the tagelectronics. The tag reader includes an electromagnetic wave (EMW)transmit antenna, RFID code receives antenna, associated electroniccircuits and an interface to couple the tag reader to the vehicleelectronics. The RFID tag is attached to the child's seat also calledthe safety seat and the tag reader is placed inside the cabin of thevehicle in spaced relation to the RFID tag. Communication between thetag reader and the tag is wireless.

The switch in the RFID tag is pressure sensitive so that the electricalcontinuity between antenna and associated electrical circuit occurs whena child is placed in the safety seat. Electrical discontinuity occurswhen the child is removed from the safety seat. When the RFID tag readeris enabled by the automobile central controller (with the appropriateconditions which will be described subsequently) it will emitelectromagnetic wave energy to energize the RFID tag device which interm transmits its RFID code to the RFID tag reader. The RFID tag readerthen relays the identified car-seat status information back to theautomobile central controller which takes predefined actions to minimizeinjury to the occupant of the safety seat.

The cost of the RFID components have been steadily decreasing, so thecost of the detection and corrective system will be relatively low.

The RFID system generates its own power, so none is needed from thevehicle power system.

Because the RFID tag is mounted on the safety seat and makes wirelessconnection with the tag reader, the safety seat is portable and can bemoved from one vehicle to the next. Of course, each of the vehicles mustbe fitted with a compatible RFID tag reader.

These benefits, advantages and others are made available to users of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic of a vehicle in which the RFID system of thepresent invention is deployed.

FIG. 2 shows a schematic of the safety seat containing the RFID tagdevice and the expanded-view of the switchable transmit/receive antennasystem of the RFID tag device according to teaching of the presentinvention.

FIG. 2A shows a block diagram of the RFID tag reader according toteaching of the present invention.

FIG. 3 shows a schematic of the RFID tag according to teachings of thepresent invention.

FIG. 4 shows schematic for the control system according to teachings ofthe present invention.

FIG. 5 shows a flow chart of the process or program used in the controlunit of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a pictorial schematic of a vehicle 100 armed with a childsafety protection system according to the teachings of the presentinvention. The child safety protection system monitors occupancy of babyseat 102 and takes corrective action, such as sounding an alarm,unlocking doors or rolling down windows if a child is left in thevehicle. The child safety protection system includes a RFID tag reader104 deployed in the roof of the vehicle. RFID tag device 106 is mountedto the baby seat 102. Because RFID tag device 106 is mounted to the babyseat 102 it may be transported and used in different vehicles providedwith a compatible RFID tag reader 104. It should also be noted that theRFID tag reader can be mounted in other locations in the cabin otherthan the roof. This is possible because RFID tag reader 104 need not bein line with RFID tag device 106 in order to exchange information. It isonly require for the RFID tag reader to be within the close proximityaround the RFID tag device.

FIG. 2 shows a schematic of the details of the baby seat 102 and theRFID tag device 106 according to the teachings of the present invention.It should be noted that throughout the different views of the drawingscommon devices or components are identified by like numerals. It shouldbe noted that throughout this document safety seat and baby seat areused interchangeably. Also, shown in FIG. 2 is an expanded internalstructure view of the RFID device 106 with its transmit/receive antenna302, antenna switch 304, and RF circuit 300. When the antenna switch 304is closed, electromagnetic wave energy from the RFID tag reader caninduce electric current through the transmit/receive antenna 302 topower up the RF circuit 300. Once being powered up, the RF circuit 300transmits its embedded RFID code through the same transmit/receiveantenna 302 for the RFID reader to read. On identifying the receive RFIDcode, the RFID reader relays the car safety seat status to theAutomobile Central Controller (describe subsequently) to take one or allthe corrective actions mentioned herein.

FIG. 2A shows a block diagram of the RFID tag reader 104. It includes aReader Control Unit 200, an Electromagnetic Wave (EMW) Emitter 202, aRFID Code Receiver 204, an EMW Transmit Antenna 206, and a RFID CodeReceive Antenna 208. During operation, when the right conditions(describe subsequently) are met, the automobile central controller sendsan RFID tag reader enable signal via interface 210 to the Reader ControlUnit 200 to enable the EMW Emitter 202 to emit EMW through the EMWTransmit Antenna 206. If antenna switch 304 (FIGS. 2 and 3) is closed,the RFID tag device 106 is energized. Once energized and powered up, theRFID tag device 106 transmits is embedded RFID code as radio signal intothe surrounding for the RFID tag reader 104 to read. Once the RFID CodeReceiver 204 receives the RFID code through the RFID Code ReceiveAntenna 208 and identified the correct code, it sends a RFID identitysignal to the Reader Control Unit 200 which in term sends thecorresponding car-seat status via interface 212 to the AutomobileCentral Controller (describe subsequently) to take one or all thecorrective actions mentioned herein. The function performed by each ofthe components shown in FIG. 2A are evident from the above description.

FIG. 3 shows a schematic for RFID tag device 106 which is substantiallythe same as the schematic shown in FIG. 2. RFID tag device 106 includesRFID tag device circuit 300 which is an off the shelf item detail ofwhich will not be given. When a child or infant is sitting in safetyseat 102 switch 304 closes and RFID tag device 106 is configured toreceive electromagnetic wave energy from RFID tag reader 104 and in turntransmits its ID to said tag reader 104.

FIG. 4 shows in block diagram of the overall RFID child safety seatsystem 400. The diagram shows interaction between RFID tag reader 104and components in the automobile in which the system is mounted. Thesystem includes the automobile main control unit 402. This main controlunit could be a computer in which an application program is executed tocarry out the function necessary to implement the child protectionaccording to the teachings of the present invention.

As stated previously, communication between RFID tag device 106 and RFIDtag reader 104 is wireless. The automobile main control unit 402 isconnected over a separate transmission channel to the car ignitionswitch (SW) sensor 404, car door switch sensor 406, auto alarm 408,light alarm 410, car window open switch 412 and RFID reader 104. Forcompleteness, the RFID Tag 106 is shown mounted in spaced relationshipto the RFID reader. The car switch sensor 404 senses the state of thevehicle ignition switch and indicates whether the switch is on or off.Car door switch sensor 404 senses the state of the doors in the vehicleand forward signal to the main control unit indicating whether the doorsare closed or open. The RFID tag reader 104 receives enabling signalfrom main control unit 402. On receiving this signal the RFID reader 104is now in the state to emit electromagnetic wave energy to enable andcommunicate with the RFID tag device 106. The conditions which causesthe main control unit 402 to issue a read enable signal to RFID tagreader 104 will be discussed subsequently.

Still referring to FIG. 4 the auto alarm 408, light alarm 410 and thecar window open switch 412 are all activated when the control unit 402determines that a child is left in the infant seat and the car ignitionswitch is off, the car doors are closed and the RFID reader is returninga positive child engage or child present signal.

FIG. 5 shows a flow chart for an application program which can beexecuted in the main control unit 402 to carry out the steps necessaryto implement the child safety protection according to the teachings ofthe present invention. The program enters at block 502 and descends intoblock 504 whereat sensor 404 is interrogated to determine the state ofthe ignition switch. If the car's ignition switch is on, the programloops; otherwise, (i.e. car's ignition off) the program exits along theyes path into block 506 whereat the main control unit 402 outputs thereader enabled signal to enable the RFID tag reader 104 to emitelectromagnetic wave energy to its proximity neighborhood. The readeremitted electromagnetic wave energy is collected by external switchableantenna 302 of the RFID device 106. If a child was in the safety seatswitch 304 would have been closed and the RFID tag device circuit 300would have been energized by the received signal. As a consequence aradio RFID tag code is transmitted from the RFID tag device 106. TheRFID tag code includes the identity (tag number) of the tag device. Onreceiving the identity tag code the RFID reader returns a signal to themain control unit 402.

Referring again to FIG. 5 if at block 508 the return control signalindicates the child seat is not engaged (empty) the program exits alongthe no path and loops. If the signal in 508 indicates that the childseat is engaged (occupied) the program descends along the yes path intoblock 510 whereat the program waits for a preset time interval and thendescends into block 512. In block 512 the program tests if the childseat is engaged. As stated above this is done by the signal that isreturned from the RFID reader to control unit 402. If the safety seat isempty the program exits along the no path and loops. If the safety seatis occupied the program exits along the yes path into block 514. Inblock 514 the controller takes corrective actions, such as activating anaudio alarm, light alarm, move windows to down position etc. The programthen descends into block 516 whereat it checks if the child is in theseat. If the child is not in the seat the program exits along the nopath and loop. If the child is in the seat the program descends intoblock 518 whereat an alarm is activated and the program loops back toblock 516 to repeat the action previously discussed.

As stated above the purpose of this invention is to detect when a childis left in a safety seat while the vehicle is unattended and to takecorrective action to prevent injury to the child. The switch 304 (FIG.3) of the RFID tag device 106 can be a pressure switch which is closedby the weight of the child in the safety seat. An alternative approachwould be to close the switch when the safety buckle of the safety seatis engaged, as is required by law to protect the child. Of course, othertechniques for closing the switch 304 can be implemented by one skilledin the art without deviating from the spirit or scope of the invention.

So long as switch 304 is open, the RFID tag device is not in a state totransmit or receive information from the RFID tag reader. Switch 304closes when an object, such as a child, is in the safety seat 102. Withthe tag device 106 armed (i.e. switch 304 is closed) if the RFID reader104 is enabled it will send out electromagnetic waves (EM waves) wavesto energize to the antenna 302 of the RFID tag device. As stated abovethe RFID reader is enabled if the vehicle ignition switch is in the offstate. With the antenna switch of the RFID tag device closed, the EMwaves from the RFID reader are received as induced energy in the RFIDtag device and Power up the RFID tag device. Once the RFID tag device isenergized it can transmit its identifying code (ID) to the same externalantenna 302 from which it has received the energizing signals. Once theRFID tag code is received by the RFID reader it indicates that anobject, such as a child, is in the safety seat. The RFID reader thenoutputs reader return signals to the main control unit. The main controlunit uses the signals to take corrective action as set forth above.

Even though the present invention has been described with references tospecific embodiment this should not be construed as limitation in thescope of the invention as claimed herein. It is within the skills of oneskilled in the art to make obvious adjustments and changes withoutdeviating from the scope and spirit of the claimed invention.

1. A system to be used in a vehicle to prevent injury to a child left ina safety seat including; an RFID reader operatively mounted in apassenger's compartment of a vehicle; a controller operatively coupledto said RFID reader, wherein the controller provides first and secondenabling signals to the RFID reader that causes the RFID reader totransmit first and second electromagnetic signals, wherein thecontroller is configured to wait for a predetermined, non-zero gap oftime between providing the first enabling signal and the second enablingsignal; a safety seat in which an RFID tag is embedded; the RFID tagcomprising a sensor configured to sense a presence of a child in thesafety seat; a first sensor configured to monitor an ignition switch ofthe vehicle to detect if said ignition switch is off operatively, thefirst sensor coupled to the controller; and a second sensor configuredto monitor doors of the vehicle to detect when said doors are closed,the second sensor operatively coupled to the controller; wherein theRFID tag is configured to receive the first and the secondelectromagnetic signals and responsively emit an electromagneticidentification signal when the sensor senses the presence of the child;wherein the RFID reader is configured to receive the identificationsignal and in response thereto forward an indication to the controller;and wherein the controller is configured to initiate an alarm inresponse the first sensor detecting if said ignition switch is offoperatively, the second sensor detecting said doors are closed, and theforwarded indication.
 2. The system of claim 1 wherein said controlleris configured to sound the alarm if predefined conditions are met. 3.The system of claim 2 wherein the predefined conditions include receiptof first and second identification signals from the RFID tag thatcorrespond to the first and second electromagnetic signals, wherein thefirst and second identification signals indicate that the sensor sensesthe presence of the child.
 4. A system for protecting children orinfants from being left in a vehicle comprising: a safety seat in whichan RFID tag is embedded, the RFID tag comprising a sensor configured tosense a child buckled in the safety seat; an RFID tag reader operativelymounted in the cabin of a vehicle; a sensor configured to monitor atleast one of: an ignition switch of the vehicle to detect if saidignition switch is off operatively; and doors of the vehicle to detectwhen said doors are closed; a computer coupled to sensor and the RFIDtag reader; and a computer readable program installed on said computer,said computer readable program including: a first instruction modulebeing responsive to first signals from the sensor to activate the RFIDtag reader, the first signals indicating at least one of: said ignitionswitch is off operatively; and said doors are closed; a secondinstruction module being responsive to second signals from the RFID tagthat indicate that a child is buckled into the safety seat, the secondinstruction module configured to wait a predetermined amount of timeand, after passage of the predetermined amount of time, to re-activatethe RFID tag reader; and a third instruction module being responsive tothird signals from the RFID tag that indicate that the child remainsbuckled into the safety seat to take an action to prevent injury to thechild.
 5. A method for preventing injury to a child left in a safetyseat, comprising: operatively mounting an RFID reader in a passenger'scompartment of a vehicle; a controller operatively coupled to said RFIDreader providing a first enabling signal to the RFID reader; thecontroller waiting for a predetermined, non-zero gap of time; acontroller providing a second enabling signal to the RFID reader afterthe waiting; in response to the first and second enabling signals, theRFID reader transmitting first and second electromagnetic signals; anRFID tag sensor embedded in a safety seat sensing a presence of a childin the safety seat; a first sensor monitoring an ignition switch of thevehicle to detect if said ignition switch is off operatively, the firstsensor coupled to the controller; a second sensor monitoring doors ofthe vehicle to detect when said doors are closed, the second sensoroperatively coupled to the controller; in response to the RFID tagsensor sensing the presence of the child, the RFID tag receiving thefirst and the second electromagnetic signals and responsively emittingan electromagnetic identification signal; the RFID reader receiving theidentification signal and responsively forwarding an indication to thecontroller; and the controller initiating an alarm in response the firstsensor detecting said ignition switch is off operatively, the secondsensor detecting said doors are closed, and the forwarded indication.